Orthographic Projection is a way of drawing an object
from different directions. Usually a front, side and plan view are drawn
so that a person looking at the drawing can see all the important sides.
Orthographic drawings are useful especially when a design has been
developed to a stage whereby it is almost ready to manufacture.

IMPORTANT: There
are two ways of drawing in orthographic - First
Angle and Third Angle.
They differ only in the position of the plan, front and side views.
Below is an example of third angle projection.

An L-shaped object.

The Plan View of the L-shape is drawn as a
'birds eye' view, a view from above.The Front View is drawn as if
stood in front of the L-shape.The Side View is drawn as if stood at
the side.

The correct position of each view is shown below. They have been drawn
very accurately, using T-Squares and set squares.

Another example of third angle orthographic
projection is shown below. Follow the blue, red and green guidelines as
the front, side and plan view are constructed.